Latch release mechanism



Feb. 26, 1952 v, MEAD 2,586,847

LATCH RELEASE MECHANISM Filed Feb. 13. 1946 c 5 I VIHCENT A. MEAD Patented Feb. 26, 1952 LATCH RELEASE MECHANISM Vincent A. Mead", United StatesNavy' Application.February13, 1946,,Serial No. 647,408

Claims.

(Granted under. the. act of. March 3,1883, asamended April 30, 1928;. 370 O G; 757-) Thisinvention relates to alatch release mechanism and particularly to a release mechanism for submerged doors or hatches on aircraft, vessels; or receptacles.

This application is a continuation-in-part of application No. 593,898 filed May 15, 1945 and now Patent Number 2,470,783, issued May- 24', 1949.

Great difficulty has been encountered in the case of sunken aircraft, receptacles, and the like in opening. escape doors and hatches because of hydrostatic pressure from the outside. This has oftenresulted in serious loss of life and property and'hascreated a need for a-latchingmechanism which not only provides manual unlocking means but utilizesv hydrostatic pressure to open the hatch and permit escape.

An object of this invention is to utilize a single latching hydrostatic'release mechanism for doors or hatches in which the'release can be unlocked either manually or by hydrostatic pressure.

Details of the. invention. are described in connection with'th'e'following' drawings in which:

Fig; 1 is an elevation of the latching mecha=-- nism;

Fig. 2 is a plan view;

Fig. 3 is a. planviewof the mounting plate;

Fig. 4 shows the latch member; and

Fig. 5 isan elevation of the piston rod.

In thedrawings, Figs. 1 and 2'show the latching mechanism secured to the escape door or hatch 22 on aircraft. Essentially, the latching device is intended for. use onairplanes. However, itiisaapparent that it can. also be used on any'vessel or receptacle which might become submerged, and should be of great value in automatically releasing life rafts and other life-saving equipment.

The latching mechanism is secured to the outside of the hatch and is provided with latch I which engagesthe fuselage or bulkhead 23 of the sunken plane or receptacle. It will be apparent that by unlocking the latch I hydrostatic pressure on the outside of the hatch will force it inwardly when submerged, thereby permitting escape. The present latching mechanism is provided with both manual and hydrostatic devices for unlocking the latch, as will become apparent as the description proceeds.

The latching mechanism is provided with mounting plate Ill adapted to be secured to the hatch, as shown, by suitable means such as rivets so as to become in effect a part of the hatch. Details of the mounting plate are shown in Fig. 3, It will be seen that mounting plate I0 is pro- 2. vided with slot 24 ataitszforward end and with opening 25 near-its center portion for a purpose later-described.

Angular brackets-20 are secured to mounting plate ID on opposite sides of slot in any suitparent that pin I5 when within radialv slot 21 looks latch member I against rotation. Withdrawal or retraction of pin I5- from radial slot 21 into the arcuateslot unlocks latch member I and permits free movement of locking pin I5 in arcuate slot26, thereby leaving latch member I freeto rotate on. pin I9, as permitted by notch 24 and a corresponding underlying opening (not visible) in the door 22. In locked position latch member Iengages bulkhead or fuselage Z3 and prevents opening of the hatch 22. However, when unlocked, the hatch can be readily opened; and if submerged. hydrostatic pressure on the outside surface ofthe door or hatch will supply the necessary, force to. open the door and permit escape.

Locking pin I5T'can be retracted in one of sev eral ways, each of'which will become apparent as the description proceeds.

CylinderZ, containing piston M, is affixed to mounting plate I'Ufby means of U-shaped strap 3. Piston. I I may be a gasket without departing from the scopeof. theinvention. Piston rod 5 is connected to the piston" and' projects forward terminating in an elongated slot 28 as shown in Fig. 5. Cylinder 2, closed at one end and open at the piston rod end, is covered with perforated disc 4. The perforations permit water to enter the cylinder and to thereby apply a force to move the piston against the air cushion in the back of the cylinder.

The forward end of piston rod 5 is received by release fitting 6. This release fitting is preferably of substantially angular shape. The upright leg is provided with. a perforation of a size to receive the forward end of piston rod 5. Pin I6 extends through elongated slot 28 to permit limited relative movement between release fitting 6 and piston rod 5. Spring II extends between release fitting 6 and perforated disc 4 to urge the release fitting forward. The lower portion of angular release fitting 6 consists of spaced legs which contain locking pin I5. Forward movement of the release fitting causes locking pin l5 to be inserted in radial slot 21, thereby locking latch member I. Conversely, retraction of release fitting 6 results in retraction of locking pin 15 permitting latch l to rotate on pin I9, thereby permitting the hatch to be opened by means of properly applied manual or hydrostatic forces.

Manual means are provided to supplement the hydrostatic piston-operated relase. Lines 29 are shown extending from release fitting 6 to the pilot, whereby the release fitting and locking pin can be retracted.

Another manual means is provided as shown. This consists of link arms 9 pivoted to opposite sides of U-shaped strap 3 and link arms 8 provided with elongated slots at the forward end pivoted on opposite sides of release fitting 6 to locking pin 15. Link arms 8 and 9 are pivotally connected together and to button I by means of suitable pins ll. Button 1 extends through perforation 25 in mounting plate I and is accessible on the inside of the door. Outward manual pressure on the button will cause link arms 8 and 9 to swing with a toggle action and thus retract the release pin and fitting.

Elongated slot in link arms 8 and elongated slot in piston rod permit sufiicient free play so that movement of one operating means can take place Without interference from the other operating means.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto, since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon o therefor.

What is claimed is:

1. A latch for securing a door to a wall comprising, a latching member and means pivotally 4 opened; a transverse locking pin in the radial portion of the slot and bridging the door slot and movable into said arcuate portion; and unlocking means connected to said pin and operable to force it from said radial portion into said arcuate portion.

2. In the combination of claim 1, said unlocking means comprising a pair of toggle joint arms connected to the ends of said pin, and to said door, and mechanism for shifting said arms.

3. In the combination of claim 1, said unlocking means comprising mechanism operable from the inside of the door structure.

4. In the combination of claim 1, said unlocking means comprising mechanism operable externally of the door structure.

5. A latching mechanism comprising a mounting plate; a latch plate secured to said mounting plate for pivotal movement normal to the plane of the mounting plate, said latch plate having an engaging member radially projecting from the edge thereof, an arcuate slot concentric to the latch plate pivot and a radial slot communicating with said arcuate slot; locking means including a pin positioned within said radial slot and movable to said arcuate slot and including stops integral with said mounting plate and engageable with the pin ends for retaining the latch plate in fixed position while said pin is within said radial slot; and lock-release means for normally retaining said pin in said radial slot but movable to force said pin outwardly in said radial slot into said arcuate slot, thereby to permit rotation of said latch plate and release of said latch.

VINCENT A. MEAD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 222,577 Coulter Dec. 16, 1879 612,593 Webster et a1. Jan. 9, 1894 1,007,398 Snider Oct. 31, 1911 1,024,603 Schmidgall Apr. 3, 1912 1,038,624 Messick Sept. 17, 1912 1,336,430 Gustafson Apr. 13, 1920 1,462,637 Fetner July 24, 1923 1,541,046 Hall June 9, 1925 1,937,978 Miller Dec. 5, 1933 2,274,711 Krause Mar. 3, 1942 

